/*
* Copyright 2010 Tilera Corporation. All Rights Reserved.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation, version 2.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
* NON INFRINGEMENT. See the GNU General Public License for
* more details.
*
* based on machine_kexec.c from other architectures in linux-2.6.18
*/
#include <linux/mm.h>
#include <linux/kexec.h>
#include <linux/delay.h>
#include <linux/reboot.h>
#include <linux/errno.h>
#include <linux/vmalloc.h>
#include <linux/cpumask.h>
#include <linux/kernel.h>
#include <linux/elf.h>
#include <linux/highmem.h>
#include <linux/mmu_context.h>
#include <linux/io.h>
#include <linux/timex.h>
#include <asm/pgtable.h>
#include <asm/pgalloc.h>
#include <asm/cacheflush.h>
#include <asm/checksum.h>
#include <hv/hypervisor.h>
/*
* This stuff is not in elf.h and is not in any other kernel include.
* This stuff is needed below in the little boot notes parser to
* extract the command line so we can pass it to the hypervisor.
*/
struct Elf32_Bhdr {
Elf32_Word b_signature;
Elf32_Word b_size;
Elf32_Half b_checksum;
Elf32_Half b_records;
};
#define ELF_BOOT_MAGIC 0x0E1FB007
#define EBN_COMMAND_LINE 0x00000004
#define roundupsz(X) (((X) + 3) & ~3)
/* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
void machine_shutdown(void)
{
/*
* Normally we would stop all the other processors here, but
* the check in machine_kexec_prepare below ensures we'll only
* get this far if we've been booted with "nosmp" on the
* command line or without CONFIG_SMP so there's nothing to do
* here (for now).
*/
}
void machine_crash_shutdown(struct pt_regs *regs)
{
/*
* Cannot happen. This type of kexec is disabled on this
* architecture (and enforced in machine_kexec_prepare below).
*/
}
int machine_kexec_prepare(struct kimage *image)
{
if (num_online_cpus() > 1) {
pr_warning("%s: detected attempt to kexec "
"with num_online_cpus() > 1\n",
__func__);
return -ENOSYS;
}
if (image->type != KEXEC_TYPE_DEFAULT) {
pr_warning("%s: detected attempt to kexec "
"with unsupported type: %d\n",
__func__,
image->type);
return -ENOSYS;
}
return 0;
}
void machine_kexec_cleanup(struct kimage *image)
{
/*
* We did nothing in machine_kexec_prepare,
* so we have nothing to do here.
*/
}
/*
* If we can find elf boot notes on this page, return the command
* line. Otherwise, silently return null. Somewhat kludgy, but no
* good way to do this without significantly rearchitecting the
* architecture-independent kexec code.
*/
static unsigned char *kexec_bn2cl(void *pg)
{
struct Elf32_Bhdr *bhdrp;
Elf32_Nhdr *nhdrp;
unsigned char *desc;
unsigned char *command_line;
__sum16 csum;
bhdrp = (struct Elf32_Bhdr *) pg;
/*
* This routine is invoked for every source page, so make
* sure to quietly ignore every impossible page.
*/
if (bhdrp->b_signature != ELF_BOOT_MAGIC ||
bhdrp->b_size > PAGE_SIZE)
return 0;
/*
* If we get a checksum mismatch, warn with the checksum
* so we can diagnose better.
*/
csum = ip_compute_csum(pg, bhdrp->b_size);
if (csum != 0) {
pr_warning("%s: bad checksum %#x (size %d)\n",
__func__, csum, bhdrp->b_size);
return 0;
}
nhdrp = (Elf32_Nhdr *) (bhdrp + 1);
while (nhdrp->n_type != EBN_COMMAND_LINE) {
desc = (unsigned char *) (nhdrp + 1);
desc += roundupsz(nhdrp->n_descsz);
nhdrp = (Elf32_Nhdr *) desc;
/* still in bounds? */
if ((unsigned char *) (nhdrp + 1) >
((unsigned char *) pg) + bhdrp->b_size) {
pr_info("%s: out of bounds\n", __func__);
return 0;
}
}
command_line = (unsigned char *) (nhdrp + 1);
desc = command_line;
while (*desc != '\0') {
desc++;
if (((unsigned long)desc & PAGE_MASK) != (unsigned long)pg) {
pr_info("%s: ran off end of page\n",
__func__);
return 0;
}
}
return command_line;
}
static void kexec_find_and_set_command_line(struct kimage *image)
{
kimage_entry_t *ptr, entry;
unsigned char *command_line = 0;
unsigned char *r;
HV_Errno hverr;
for (ptr = &image->head;
(entry = *ptr) && !(entry & IND_DONE);
ptr = (entry & IND_INDIRECTION) ?
phys_to_virt((entry & PAGE_MASK)) : ptr + 1) {
if ((entry & IND_SOURCE)) {
void *va =
kmap_atomic_pfn(entry >> PAGE_SHIFT, KM_USER0);
r = kexec_bn2cl(va);
if (r) {
command_line = r;
break;
}
kunmap_atomic(va, KM_USER0);
}
}
if (command_line != 0) {
pr_info("setting new command line to \"%s\"\n",
command_line);
hverr = hv_set_command_line(
(HV_VirtAddr) command_line, strlen(command_line));
kunmap_atomic(command_line, KM_USER0);
} else {
pr_info("%s: no command line found; making empty\n",
__func__);
hverr = hv_set_command_line((HV_VirtAddr) command_line, 0);
}
if (hverr)
pr_warning("%s: hv_set_command_line returned error: %d\n",
__func__, hverr);
}
/*
* The kexec code range-checks all its PAs, so to avoid having it run
* amok and allocate memory and then sequester it from every other
* controller, we force it to come from controller zero. We also
* disable the oom-killer since if we do end up running out of memory,
* that almost certainly won't help.
*/
struct page *kimage_alloc_pages_arch(gfp_t gfp_mask, unsigned int order)
{
gfp_mask |= __GFP_THISNODE | __GFP_NORETRY;
return alloc_pages_node(0, gfp_mask, order);
}
static void setup_quasi_va_is_pa(void)
{
HV_PTE *pgtable;
HV_PTE pte;
int i;
/*
* Flush our TLB to prevent conflicts between the previous contents
* and the new stuff we're about to add.
*/
local_flush_tlb_all();
/* setup VA is PA, at least up to PAGE_OFFSET */
pgtable = (HV_PTE *)current->mm->pgd;
pte = hv_pte(_PAGE_KERNEL | _PAGE_HUGE_PAGE);
pte = hv_pte_set_mode(pte, HV_PTE_MODE_CACHE_NO_L3);
for (i = 0; i < pgd_index(PAGE_OFFSET); i++)
pgtable[i] = pfn_pte(i << (HPAGE_SHIFT - PAGE_SHIFT), pte);
}
NORET_TYPE void machine_kexec(struct kimage *image)
{
void *reboot_code_buffer;
NORET_TYPE void (*rnk)(unsigned long, void *, unsigned long)
ATTRIB_NORET;
/* Mask all interrupts before starting to reboot. */
interrupt_mask_set_mask(~0ULL);
kexec_find_and_set_command_line(image);
/*
* Adjust the home caching of the control page to be cached on
* this cpu, and copy the assembly helper into the control
* code page, which we map in the vmalloc area.
*/
homecache_change_page_home(image->control_code_page, 0,
smp_processor_id());
reboot_code_buffer = vmap(&image->control_code_page, 1, 0,
__pgprot(_PAGE_KERNEL | _PAGE_EXECUTABLE));
memcpy(reboot_code_buffer, relocate_new_kernel,
relocate_new_kernel_size);
__flush_icache_range(
(unsigned long) reboot_code_buffer,
(unsigned long) reboot_code_buffer + relocate_new_kernel_size);
setup_quasi_va_is_pa();
/* now call it */
rnk = reboot_code_buffer;
(*rnk)(image->head, reboot_code_buffer, image->start);
}
